Dehorning tool



Nov. 17, 1953 Filed June 12 1952 V. L. FENDER DEHORNING TOOL 2 Sheets-Sheet l INVENTOR.

WHITEHEAD 8i VOGL PER Wad ATTORNEYS VERLE L. FENDER Nov. 17, 1953 2 Sh eets eet Filed June 12, 1952 m m m m VERLE ER B w rrEHEA VOGL ATTO YS Patented Nov. 17, 1953 UNITED STATES PATENT OFFICE DEHORNING TOOL Verle L. Fender, Carbondale, 0010.

Application June 12, 1952, Serial No. 293,086

9 Claims.

anew and improved dehorning tool having opposed blades with cutting edges which substantially encircle and sever the horn by cutting completely around it; (c) in a dehorning tool, opposing cutting elements which react in opposition to each other to cut a horn from both sides and thereby eliminate blunt abutment members in the tool; (d) in a dehorning tool, a pair of handles adapted to be manually pulled together to operate cutting knives, with camming elements interconnecting the handles and knives adapted to so modify and transmit the force required to cut the horn that the force required to pull the handles together remains substantially uniform throughout a dehorning operation; (e) a dehorning tool having opposing knives which move together to sever a horn but at the same time have some rotary movement to thereby lessen the crushing and increase the cutting action of the knives on the horn; and (f) a dehorning apparatus which combines a simple and compact group of elements into a rugged and sturdy unit which may be used for a long period of time.

With these and other objects in view, all of which more fully hereinafter appear, my invention comprises certain new and novel constructions, combinations and arrangements of parts and elements as hereinafter described, and as defined in the appended claims and illustrated, in preferred embodiment, in the accompanying drawing, in which:

Figure 1 is a perspective view of my dehorning device in an open horn-receiving position.

Figure 2 is a longitudinal section through the device as viewed from the indicated line 2--2 at Fig. 1.

Figure 3 is a sectional plan of the device as viewed from the indicated line 3-3 at Fig. 2.

Figure 4 isa sectional plan of the device as viewed from the indicated line 4-4 at Fig. 2, with the broken lines indicating a closed position of one of the blades.

Figure 5 is a section as taken on the indicated line 5-5 at Fig. 1.

Figure 6 is a perspective view similar to Fig. 1 but with the device closed, as after a hornsevering operation.

Figure 7 is a fragmentary section on the indicated line 11 at Fig. 3.

The common construction of dehorning tools, of the general type of my invention, usually include a head having a horn-receiving orifice therein, with a knife adapted to move across this orifice, and a pair of handles, one handle being connected to the head and the other being connected to the knife in such a manner that the knife will be moved across the orifice to sever a horn as the handles are pulled together. A necessary and common feature of such tools is an abutment to hold a horn as the knife moves to and through it from theopposite side of the orifice. Such abutment maybe the wall of the horn-receiving orifice or may be a specially constructed element carried by the head. With such apparatus, the horn severing operation involves cutting through the horn from one side to theother. The thickness of the knife causes considerable resistance to such movement and pushes the horn against the abutment with a crushing and a pulling apart of the fibers forming the horn before the knife moves completely across the hornan unsatisfactory operation which results in leaving the horn stub on the animal crushed and splintered.

' Where the knife of a dehorning tool is connected to a handle by a simple pivot, the force required to bring the handles together and move the knife into and through the horn will vary from a maximum force, as the knife begins tocut into the horn, to a much smaller force after the cutting is partially completed and the knife moves into the hollow center portion of the horn. An arrangement which operates with a uniform force upon the handles during'all stages of the operation is much more efiicient and desirable.

With the foregoing in view, the present inven-- tion was conceived and developed and comprises, in essence, a dehorning tool having a pair of knives with opposing cutting edges which are adapted to encircle a horn, thereby eliminating the need for abutments, and cam means interconnecting the handles and the knives in a manner which provides a leverage which varies as between the knives and the handles to vary the cutting force during movement of the knives through a horn while maintaining a substantially uniform force upon the handles to bring them together.

In the illustrated embodiment of my invention, the dehorning device includes a disc-shaped container head l0 formed by a pair of spaced circular cover plates I l enclosed at their peripheries by a ring 12. This head includes a hornreceiving orifice l3 in the centers of the plates l I, a handle l4 secured to and outstanding from the peripheral portion of the head in a direction radial thereto, and an arcuate slot I5 in each plate extending about one-quarter around the plates from the handle 14, which slots expose a portion of an internal disc I6, hereinafter described.

A handle I! has its inner end bifurcated and the forks aresecuredto disc [6 and are looped around the rim portion of container head 10 which lies outside the slots, and as the disc is' rotatable within the head it may be rotated, to the limits of the slots, by moving handle I! toward handle H, to position illustratedat Fig-6,

or away from handle 14 to position illustrated at Fig. 1.

The disc is formed as a container, similar to the head l0, comprising a pair of circular plates l9 spaced apart by a ring and filler blocks 2!. The'di'sc I6 is snugly but rotatably seated inside the head In and the plates IB-have horn-receiving orifices 22 which register with theorifices [3 to provide an unobstructed passageway for a horn through head l0: Each plate [9 includes a pair of arcuate slots 23 in opposing quadrants of the disc and of substantially the same arcuate extent as the slots l5.

Two diametrically opposed posts 24 extend through each slot 23' and are attached to each cover plate H. A roller sleeve 25 is mounted upon each post 24 between the cover plates H and extends through the disc "5. It follows that rotation of the disc IG within the head if) changes the disc and slot 23 positions relative to posts 24.

Diametrically opposed knives 26 lie within the disc Hi. The cutting edge of each knife 28 is a semi-circle which, when in retracted position as shown in full lines at Fig. 4, registers with the orifices 22- of the disc H5. The termini of the two knives 26 overlap each other even when in retracted position, and as they move across the orifice 22 (as later described), their common contactin'g, faces slide, one upon the other, along the central plane 21' of the unit. Each knife 26 is mounted upon a pivot 28 which pivots are diametrically opposite each other. The pivot of each knife is carried by the plate l9 which is closest to such knife and the pivots extend only to the center plane 27. By terminating each pivot at the center plane 21., each knife 26 can move past the pivot of the other knife to a closed position without interference, as clearly shown by the broken lines at Fig. 4.

The arcuate cutting edge of each knife is beveled whereby the cutting edges of both knives are at the adjacent faces of the knives and on the common. center plane 21. It follows that this construction not only permits the knives to swing past each other, but also holds the cutting edge of. both knives at the center plane 21 and a horn will be severed along a fiat plane and from both sides at once. To assure holding each knife in its proper plane, rollers 25 may include spacer flanges 29 in the gap between the knife with which it is associated and the opposite plate I9.

Each knife is formed as a flat plate and the back edge, opposite the cutting edge, is formed as a .cam lobe 30 which lies across the slot 23 and bears against the roller of post 24. The lobe 30 is formed in such a manner that movement and rotationof the disc within the head I0 causes the post 24 to bear against the lobe and exert pressure to move theknives inwardly into the orifices. Because of the polar symmetry of the unit, both knives contact their posts 24 and move into the orifice coincidentally as the disc I6 is rotated within the head ID, as hereinbefore described.

The cam lobe may be shaped in any manner, but preferably its shape will be such that the cutting forces of the knives will vary according to a desirable pattern with relation to the force required to pull the handles [4 and I! together. It is contemplated that an eflicientvdesign of a dehorning tool will be one inwhichgthezforce required to pull the handles l4 and I! together remains practically constant throughout the dehorning operation. To design such a cam, it must be recognized that a horn comprises a relatively hard outer layer and a comparatively hollow interior. Accordingly, the force on the cutters reaches its maximum at the initial phase of the cutting operation and decreases rapidly as the knives move into the interior portion of the horn. It follows that the lobe 30, which is based upon radial movement, increases its radius slowly at that initial operating portion 3| and then increases the radius rapidly at the final operating, portion 32. One skilled in the art can design and shape the lobe 39 in a manner which permits any predetermined relation between the pressure onthe knivesand the, force required to pull the handles together, and can design the apparatus to most efiiciently cut any given type of horn.

A knob 33 extends from each knife at the, side of the roller opposite the cam lobe 30' and provides knife retracting means. for as the handles l4 and I! are pulled apart, the rollers 25 bear against the knob 33 to move and open the knives.

In operation of this dehorning tool, it is necessary only to place the tool overa horn so thatthe horn projects. through the orifices i3, to then pull the handles togetherto sever the horn. It is to be noted that the knivesrotate about their pivots; to move together to, cut off the horn, but that there. is a certain amount of, lateral or rotative movement of each knife with respect to the other, thus drawing the knife across the horn as it cuts into the horn.. Such rotation decreases the required cutting forces, and provides a smooth finished out. With this apparatus the horn will not abut against the side of the orifice as the cutting; edges substantially encircle the horn.

While I have described" in. detail a preferred construction of my invention, those skilled in the art can devise alternatives and equivalents which are within the scope and spirit of my invention, and hence it is my desire that my protection be limited not to the details and constructions illustrated and herein described, but only by the proper scope of the appended claims.

I claim:

1. A dehorning tool comprising a body having a horn-receiving orifice, a pair of knives within this body mounted at opposite sides of the orifice and means for moving the knives toward each other across the orifices to effectuate, a horncutting operation, said knives comprising flat members adapted to overlap each other as they move across the orifice.

2. The apparatus defined in claim 1 wherein the cutting edges of said knives extend arcuately about the orifice with the knives in the. open horn-receiving position.

3. The apparatus defined in claim 2. wherein each knife is beveled to position the cutting edge at the lapping surface and thereby position the cutting edges of both knives on the plane defined rotatably carried within the head, a horn-receiving orifice extending through the head and the disc and centrally thereof, a pair of knives mounted within the disc at opposite sides of the orifice and means adapted to move the knives toward each other across said orifice responsive to the rotation of the disc within the head.

5. The apparatus defined in claim 4, including a handle connected to the head, a slot in the head exposing a portion of the disc and a handle connected to the disc through the slot, whereby movement of the handles with respect to each other effectuates rotation of the disc within the head.

6. A dehorning tool comprising a head, a hollow disc rotatably carried within the head, a horn-receiving orifice extending through the head and disc centrally thereof, arcuate slots in the disc on opposite sides of the orifice, a pair of posts mounted in the head at opposite sides of the orifice and camming means adapted to bear against the posts, and adapted, by configuration, to move the knives toward each other across said orifice responsive to the rotation of the disc within the head and the movement of the posts within the slots.

'7. A dehorning tool comprising a head, a hollow disc rotatable within-the head, a horn-receiving orifice extending through the head and disc centrally thereof, arcuate slots in the disc on opposite sides of the orifice, a pair of knives carried upon pivots within the disc at opposite sides of the orifice and adapted to swing toward each other and across the orifice. a pair of posts mounted in the head at opposite sides of the orifice and extending through said arcuate slots, the body of each knife having its edge remote from the orifice cammed and extending transversely across a slot in the disc and positioned to abut against a post, whereby rotation of the disc within the head to effectuate the change of position of each post within and relative to its slot swings the knife across the orifice.

8. The apparatus defined in claim '7 wherein said cam is configurated to define a reach 01' slow movement of the blade with respect to rotation of the disc within the head followed by a, reach of fast movement.

9. The apparatus defined in claim 7, including a stub on the knife adapted to bear against the post at the side opposite to the cam to reverse the movement of the knife as the movement of the disc within the head is reversed.

VERLE L. FENDER.

N me Date Number a Thompson Jan. 22, 1952 

